GaAs光阴极量子效率分布测量  

Quantum efficiency mapping of the GaAs photocathode

作　　者：杨仁俊[1,2] 肖德鑫[1] 李凯[1] 吴岱[1] 潘清[1] 王建新[1] 杨兴繁[1] 

机构地区：[1]中国工程物理研究院应用电子学研究所,四川绵阳621900 [2]中国工程物理研究院研究生部,北京100088

出　　处：《强激光与粒子束》2015年第5期272-276,共5页High Power Laser and Particle Beams

基　　金：国家自然科学基金项目(11475159;11305165);中国工程物理研究院发展基金项目(2013B0401073;2014B0402069;2014B0402070)

摘　　要：基于负电子亲和势GaAs光阴极直流高压注入器,设计并搭建了国内首套光阴极量子效率分布测量系统。该系统利用单透镜实现逐点扫描,并采用LabVIEW进行控制和数据读写。实验表明,该系统单点采样时间小于2.3s,分辨率优于0.32mm。初步测量了GaAs阴极的量子效率分布,观察到量子效率分布及其衰减的不均匀性,量子效率较高区域的衰减速率更低。An accurate quantum efficiency （QE） map is very important in characterizing the performances of semiconductor photocathodes. This paper presents the study of a QE mapping system built on a DC high-voltage GaAs photocathode injector. A focusing lens is used to move the laser spot to different locations on the photocathode and to map the quantum efficiency. The con trol system and the data acquisition are established by LabVIEW. With a single sampling time of 2.3 s and a resolution of 0.32 mm, several quantum efficiency maps of the GaAs photocathode have been measured during 330 h. Both the distribution and the decay of the quantum efficiency have been observed from these maps as non-uniform. The quantum efficiency in the high quantum efficiency region decays slower than that in other regions. This QE mapping system is critically useful in improving the preparation technique of the photocathode.

关 键 词：砷化镓光阴极 量子效率 光阴极注入器 阴极寿命 

分 类 号：TL53[核科学技术—核技术及应用] O462.3[理学—电子物理学]